1. Field of the Invention
This invention generally relates to a bearing assembly for bicycle parts. More specifically, the present invention relates to a bicycle bearing assembly, which has inner and outer members formed by rolling, instead of by machining.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. Also, bicycle manufacturers are also constantly improving the manufacturing techniques utilized to make the various components for reducing costs. One particular component of bicycles, which have been extensively redesigned over the past years, is the bearing assemblies, which are used to form the bottom bracket and the front and rear hubs.
The bottom bracket has a shell fixed to the frame of the bicycle and a spindle rotatably mounted within a portion of the bicycle frame. Bearings are installed between the outer tubular member and the spindle such that the outer tubular member rotates freely about the spindle. Pedals are coupled to the ends of the spindle by a pair of cranks. An example of a prior art bottom bracket is disclosed in U.S. Pat. No. 4,150,859 to Segawa.
Similarly, front and rear hubs for a bicycle have a hub axle or spindle rotatably coupled within an outer tubular member or shell. In the case of a hub, the hub axle or spindle is fixedly coupled to the bicycle frame and the outer tubular member or shell is fixedly coupled to the spokes of a bicycle wheel such that the bicycle wheel rotates about the axis of the hub axle or spindle. Bearings are installed between the outer tubular member and the hub axle or spindle such that the outer tubular member rotates freely about the hub axle or spindle.
The outer tubular members and the spindles are typically constructed through expensive machine operations. In particular, it is important that the bearing engagement surfaces of the outer tubular member and the spindle be smooth and without imperfections so that the spindle and outer tubular member rotate smoothly relative to each other via the ball bearings or bearing members. Typically, these machining operations produce small micro-grooves, which adversely affect the relative rotational movement between the spindle and the outer tubular member.
In view of the above, there exists a need for an improved a bicycle bearing assembly which overcomes the problems in the prior art devices and which is relatively easy to manufacture and assembly. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.